This invention relates generally to a pipe and conduit hanger of the type adapted to be attached to a threaded support rod depending vertically from a structural steel beam, for example, and more particularly to such a hanger which is vertically adjustable on the support rod for supporting a pipe or conduit in generally horizontal position at a selected elevation.
One such pipe hanger presently on the market comprises a generally U-shaped metal strap, the upper ends of which are bent inwardly to form overlapping horizontal flanges. The hanger also includes a separate metal insert having a circular head and a shank extending up through aligned holes in the flanges of the metal strap. The shank of the insert is internally threaded to receive an externally threaded stud or support rod. The elevation of the hanger is adjustable by threading the insert up and down on the stud.
This prior art hanger has a serious drawback, however, in that the strap and the insert are two separate unconnected parts which tend to become separated during shipment and during handling in the field. Moreover, installation of the hanger is made more difficult due to the fact that two separate pieces must be handled. In addition, this prior art hanger in general, and the insert in particular, are relatively expensive to produce.
The prior art hanger shown and described in U.S. Pat. No. 2,996,274 is similar to the hanger described above, except that the metal insert is formed to be held captive (but also rotatable) in the opening in the lower flange of the U-shaped strap, thereby avoiding the problem of the strap and insert becoming separated. However, this insert is even more expensive to produce. Moreover, attachment of the hanger to a support rod may be inconvenient in that, according to the specification of the patent, the legs of the U-shaped strap must be squeezed together to bring the flange holes into alignment, and the legs then manually held in that position while the insert is moved to a position in which it may be threaded onto a support rod.
U.S. Pat. No. 1,579,419 shows another pipe hanger generally in the field of this invention.